Wednesday, August 09, 2006

Migraines: the known unknowns and the unknown unknowns

Doctors are finding that a lot of what they thought they knew about migraine headaches is wrong.

[T]here is growing evidence that almost all so-called sinus headaches are really migraines. ... Though long believed to be primary vascular headaches, the result of constriction then expansion of blood vessels in the head, migraines are now recognized to stem from neural changes in the brain and the release of neuroinflammatory peptides that in turn constrict blood vessels. The headache often begins before these vessels dilate. The inflammatory peptides sensitize nerve fibers that then respond to innocuous stimuli, like blood vessel pulses, causing the pain of migraine.